// 自定义函数
@function square($num) {
  @return $num * $num;
}
div {
  width: square(2);
  height: 200px;
}
// https://sass-lang.com/documentation/modules/string/
// @use "sass:map";
$config: (
  small: 20px,
  large: 30px,
);
p {
  font-size: map-get($config,small);
}
